The error message reported is what you get when iMS cannot connect to it's CONFIG ldap server, to gather configuration information.
If you use two ldap servers, check that the config instance is running. If you changed DNS or something like that, you may have to re-set some configuration, and that's harder when you can't get to the config ldap to do it.
Check if you can run
configutil
without a problem.
local.ugldaphost is your users/groups ldap
local.ldaphost is your config ldap
To make a "local" change (not to ldap),
configutil -o -l <thing to be changed> -v <new value>
this will write to a local file, and so will work, even if you can't get to ldap.
If nothing was changed, then you may have a problem with your ldap server. . .